Whether it is past, present or future energy sources doesn't really matter that much, Any 24x7x365 power grid that's up and running to provide all the energy each of us wants is a form of suicide.

Past Energy
The fossil fuel source of our current global industrial civilization is nearing its terminal phase. Most informed people now recognize that It is inviting disaster to continue burning oil at the rate we do.

Present Energy
The current alternative electric energy sources are primarily wind and solar. Bother are intermittent and variable.

Both require consuming vast amounts of fossil fuels to put in place,

Both require high levels of industrialization, transportation and technical skills to maintain.

Both require expensive power storage capability,

Currently the large scale windmills used to support the Grid economically require towers that are hundreds of feet tall. When one gets into trouble it is difficult to to do much about it. Who wants to climb a three hundred foot ladder to face a raging fire?

Chernobyl and Fukushima should have made it obvious that nuclear power is not a viable alternative energy. It will not save us, despite its embrace by James Lovelock. Lovelock, you may remember was the discoverer of the hypothesis of Gaia - that the Earth's environmental systems are interlocked in a living self-supporting and self-reinforcing network of relationships.

Lovelock's well reasoned fear is that without nuclear power we won't be able to keep civilization going. The problem is that we won't really be able to keep the nuclear plants operational. They require too much fossil fuel based technology for maintenance and repair.

The best plan, while we have the fossil fuel, would be to dismantle and shield ourselves from the intensely poisonous nuclear material we have already created. Once any serious collapse happens there will be no possibility of keeping ourselves and the rest of life on the planet safe.

Future Energy
The seductive idea that scientists will finally find a pollution free and limitless supply of energy from some yet to be mastered technology is comforting to those embedded in the growth and consumption based civilization most humans find themselves in.

Since the detonation first thermonuclear hydrogen bomb in 1953 scientists have been promising safe light-element atomic energy from nuclear fusion. Serious efforts to achieve this became a technological race between the US and USSR that ran parallel to the space race. The US got to the moon. Nobody built a fusion reactor.

We commented there that the last thing we need to do is give humanity unlimited amounts of power to run global industrial civilization. Fusion power would only increase world resource extraction and consumption - more iron, more copper, more aluminum, more titanium, more plastic.

And so...
The conclusion that keeps emerging from many directions is that large scale centralized electric power generation is simply too destructive to life on Earth. We need to make the adjustment to less energy use from distributed small scale sources as smooth as possible and wind down the Grid.